Working on your muscles could help delay the onset of Alzheimer's symptoms, researchers have revealed.
Researchers from the Federal University of São Paulo and the University of São Paulo in Brazil have uncovered strong evidence that resistance training – where muscles are worked against a weight or a force – could have significant consequences for the brains of dementia patients.
Before you hurriedly renew your gym membership or break out the home exercise equipment, it's worth bearing in mind that this was a mouse model study. Nevertheless, the same principles are likely to apply to humans.
"This confirms that physical activity can reverse neuropathological alterations that cause clinical symptoms of the disease," says neuroscientist Henrique Correia Campos, from the Federal University of São Paulo (UNIFESP).
Mice with a genetic mutation that causes beta-amyloid plaques to build up in the brain – as seen in individuals with Alzheimer's – were put through a four-week resistance exercise training program involving ladders and weights before being compared to mice without the mutation.
Not only was the build-up of plaques reduced after exercise, levels of the hormone corticosterone in the plasma of the weight-training mice were similar to plasma levels in mice from the control group. Corticosterone equates to cortisol in humans, which is produced when the body is under stress, and has been previously linked to Alzheimer's.
As Alzheimer's disease and other forms of dementia can produce wandering and restlessness in mice, the team also tested the beta-amyloid plaque mice for anxiety. Here again the resistance training seemed to help.
"We also observed the animals' behavior to assess their anxiety in the open field test and found that resistance exercise reduced hyperlocomotion to similar levels to the controls among mice with the phenotype associated with Alzheimer's," says neuroscientist Deidiane Elisa Ribeiro from the University of São Paulo in Brazil.
Aside from keeping in mind potential differences between mouse and human physiology, the exact role protein plaques play in Alzheimer's is still debated, leaving room for debate over the extent of benefits resistance training might have for dementia patients.
Still, resistance training has few downsides, especially as we age. It increases muscle mass and strength, boosts bone density, and helps with balance and makes everyday tasks easier to perform. It's also one of those exercises that's easier to keep up as you get older, leaving few excuses not add it to your daily routine. The earlier the better!
Previous studies have noted how this particular type of exercise can strengthen connections in the brain that are likely to break as dementia sets in, so it looks as though activity like this can guard against dementia as well as alleviate the symptoms – assuming the same effects are shown in humans of course.
Scientists are still trying to untangle the relationship between Alzheimer's, its root causes, and the general consequences of the body getting older, but resistance training could potentially help in all three areas.
"The main possible reason for this effectiveness is the anti-inflammatory action of resistance exercise," says UNIFESP neurophysiologist Beatriz Monteiro Longo.
The research has been published in Frontiers in Neuroscience.